Hydrocraft planing-surface.



S; V. DE BOLOTOFF.

HYDROCRAFT PLANING SURFACE.

APPLICATION man ma. 1, 191a.

ll ,3GJ1 11, 7 Psmented Apr. 29, 19119.

SERGE VINCENT DE BOLOI'OFE, OF LONDON, ENG.

nnoonarr rnanrne-soaracn eonora Specification of Letters Patent. Patented Apr. 29, 1919.

Application flle'd February 1,1918. serial No. 21%,867.

' has for its object to provide-means whereby shock ma be absorbed by the planing surfaces. T e word hydrocraft throughout this specification and claims is intended to cover any craft having planes which cooperate with the water to lift the craft Whether such craft also has planes which lift it completely out of the water or not.

This invention is particularly applicable to hydrocraft of the, type wherein planes are provided which are set bodily down below the level of the floating-surface (i. e. the underside of the floats or hull) whereby the craft is supported when not in motion, which planes are submer ed when the hydrocraft is stationary but li t the hydrocraft as it is driven forward so that the main float-' ing-surface is lifted above the level of the water. a

In this type of hydrocraft heretofore employed the planes have been rigid throughout but according to the'present inventlon each such plane comprises a forward and a trailin part whereof the forward part is preferab? fixed relatively to the hydrocraft and the trailing part is hinged to swing about an axis that is transverse to the direction of travel and more or less horizontal, the said trailing portion being yieldingly further su ported from a point behind the said axls for the purpose herein.- after described.

It has already been proposed to provide the floating-surfaces, that is the floats or hull, of hydrocraft with planes which are hinged at their forward end to the underside of the floating-surface and are spring-controlled at the trailing end. Although with such an arrangement the body of the float itself provides a fixed plane portion in front I of the hinged plane, it offers a large surface to the water and thus is exposed to considerable shock when striking the waves, whereas with the type of craft to which this invention applies, where the planes are set down below the level of the floating surface, a decrease of shock is obtained as the planes cut through the waves and the floatmg surface is kept either entirely free of them or onl brought into contact with the tops of the arger ones.

. One method of carrying out this invention is shown 1n the accompanying drawings in which Figure 1 is a side elevation of a hydroplane-hull with the pivoted compound plate hereinafter described applied to it,

Fig. 2 1s a diagrammatic plan of a pivoted compound plane, showing the supportlng stays in section, and

Fig. 3 is a side elevation of the same.

In the drawings the forward portion A of the plane is shown as carried rigidly by the rigid sta s D and E, fixed at their upper ends to the ull H of the hydrocraft, while the forward end of the trailing portion B is transversely pivoted or hinged at C'to the rig1dly-held forward. portion A, and the after end is similarly pivoted to the end of thestay F,'which stay would in this case be yieldingly carried in any convenient way by the hydrocraft. It may be controlled as in Fig. 1 by a s ring S in compression above the top of the s tube '1 the stay telescopes. The tube is pivoted by a pin P at its upper end to a lug L secured to the hull H. In the lower part of the tube T is a pin t passing throu h a slot w in the stay F to prevent the stay from being forced too far out of the tube.

The planes may be of any suitable crosssection (that is, a section made in the direction of travel) and have curved or flat surfaces.

As shown in Fig. 2, the forward portion A of the compound plane AB is of triangular cross-section, the upper and lower sides A and A being curved outward and having their apex in the front edge of the plane. The sides A and A are considerably longer than the base or thickness of the plane at the pivot.

The trailing portion B of the plane is also of triangular cross-section, but the upper and lower-sidesof the triangle are shown straight and much longer than the sides A and A Within a certain speed limit in smooth water, the forward and trailing portions of the compound plane operate like one ordinary rigid plane; but if the water is not smooth and the plane strikes a wave'it canthen (if both ends are-pivoted as described) yield at either end or both ends-as circumstances require. v If the speed in smooth water is increased I beyond a given point so that the resistance against the trailing portion of the plane becomes such as to overpower the yielding control therefor, then the said trailing portion can swing up about its hinged connection against the action of the yielding-control and thus decrease the angle at which it is presented to the water sothat the resistance of the latter to it does not continue to increase with the increase of speed vin the same proportion as wouldbe the case if no such yielding movement were possible.

Again, when the craft is alighting upon the water, the tail-portions of the planing surfaces will touch the water first and these can then ield to absorb shock at the moment of a i hting.

What I c aim as my invention and desire to secure 'by Letters Patent is 1.. In a-hydrocraft, the combination of,

a composite plane comprising leading and trailing portions respectively, means to sup-' port the plane from the hydrocraft in suchposition that it is situated bodily below the level of the floating-surface of the hydrocraft, means for hingingthe said trailingportion at its forward end relatively to the leading-portion and the supporting-means, toswing about an aXis that is transverse to the direction of travel and more or less horizontal, and yielding means operatively connecting the said trailing-portion to the supporting-means at a point behind the said axis of hinging, :tor the purpose described.

2. In a hydrocraft, the combination of, a

"composite plane comprising leading and trailing portions respectively, means to support the plane from the hydrocratt in such position that-it is situated bodil below the level of the floating-surface o' the hydrocraft, means for rigidly securing the leadsupporting-means, to swing about an axis that is transverse to the direction of travel and more or less horizontal, and yielding ing-portion to the supportinfg-ineans at a po nt behind the said axis 0 hinging, for the purpose described.

' means 'operatively' connecting the said trail- 1 5b 3. In a hydrocraft,'the combination of, a

composite plane comprising leading and trailing portions respectively, means to support the plane from the hydrocraft in such position that it is situated bodily below the level of the floating-surface of the hydrocraft, means for hinging the said trailingportion byits forward end to the rear of the leading-portion to swing about an axis that is transverse to the direction of travel and more or less horizontal, and yielding-means operativly connecting the said'trailing-por- 'tion to the supporting-means at a point hehind the said axis of hinging, for the purpose described.

In testimony whereof I a my signature.

SERGE VINCENT DE BOLQTOFF. 

